Concentrating solar collectors have a variety of uses, for example heating water for domestic or industrial uses, or for providing heat for power generation in a concentrating solar power plant. FIG. 1 illustrates a schematic view of a portion of a conventional concentrating solar collector installation. A solar collector assembly 100 includes two solar collector modules 101a and 101b. The modules 101a and 101b are mounted on pylons 102a-c, and can rotate about an axis 103 to track the sun. Each module includes a trough-shaped reflector 104 that reflects incoming solar radiation 105 onto a receiving tube 106. For example, the reflector 104 may be in the shape of a parabolic cylinder, and the receiving tube may be placed at the focal line of the parabolic cylinder where the reflected solar radiation is concentrated. The receiving tube 106 carries a working fluid, for example water, oil, or another working fluid, that is heated by the concentrated solar radiation. The working fluid is piped to a central location for use. For example, heated water may be carried to an industrial process or used for hydronic space heating. Alternatively, the heat transfer fluid may be carried to a power generation plant that generates electric power using heat provided by the working fluid.
While only two collector modules 101a and 101b are shown in FIG. 1, many more modules may be present, and may be arranged in rows called solar collector assemblies. The modules in a solar collector assembly are interconnected so that they rotate in unison. A drive system (not shown) placed at an end or preferably near the center of a solar collector assembly provides torque for rotating the assembly. A solar collector assembly may include as many as dozens of modules, and the collector field may include hundreds or thousands of modules.
In order to maintain proper aiming of all of the modules in a solar collector assembly to track the sun, the modules must transfer sufficient torque between them to drive the assembly and to withstand wind loading, and the modules and any torque transfer mechanism should be stiff enough that the torque is transferred without undue twisting of the assembly.
It is also desirable that parts of a solar collector installation be configured such that they can be efficiently shipped to an installation site and assembled easily at the installation site.